This circuit for UHF between 800 and 1 000 MHz was found in an American documentation from the 90's. The integrated circuit is from that time, uncommon today.
With this circuit it is possible to use a common hair dryer as a hand dryer. The circuit is timed...
This circuit was obtained from an English magazine from 1979, but can be easily assembled today...
This circuit was obtained in a 1975 magazine, but it can be easily assembled using BC548...